Share the snafus and breakthroughs to save the next person some time.
For me, I spent about 2h troubleshooting some connectivity issues only to realize that the issue stemmed from the DNS providers I chose in /etc/resolv.conf not playing nice w/ dynamic DNS domains.
Apparently, some of them get a blanket URL block for DDNS. Quad9 and Cloudflare were both a no go. Google works (but I am not self-hosting netbird to use big tech) so I settled on an AGH DNS IP (nameserver 100.87.230.104) instead.